From DE 101 47 536 A1, an internal combustion engine is known in which in an inlet system an exhaust heat exchanger thermally connected to the exhaust gas system is provided, wherein the heat exchanger can be activated or deactivated via control valves configured as flaps. The exhaust heat exchanger can be bypassed by means of bypass lines both on the side of the inlet system and on the side of the outlet system.
In addition, from DE 103 47 834 A1 a diesel combustion engine comprising an exhaust gas aftertreatment system is known. The exhaust gas recirculation system comprises a two-path system, wherein in a first path a cooling unit is provided and the second path is connected in parallel to the first path. In addition, a charge-air cooler is disposed in the charge-air supply line.
From DE 10 2004 021 386 A1, an internal combustion engine comprising an exhaust gas recirculation system is known, wherein two heat exchangers are provided in an exhaust gas recirculation line. The exhaust gas flowing through the two heat exchangers is cooled thereby. A further heat exchanger is disposed in a charge-air line.
In addition, from FR 287 64 17 an internal combustion engine is known, wherein two heat exchangers are provided in series in a waste gas recirculation line. A three-way valve is disposed upstream of the first heat exchanger and between the two heat exchangers, respectively, a bypass branching off therefrom. Depending on the load state of the internal combustion engine, the waste gas can be conducted through both heat exchangers or through the bypass. If the engine is subject to average load, the waste gas is conducted through the first heat exchanger and past the second heat exchanger. If the first valve disposed upstream of the two heat exchangers is closed to the flow through the downstream heat exchanger, a considerable portion of the waste gas is always routed via the bypass past the second heat exchanger, even if the valve provided between the two heat exchangers is then open. With the known internal combustion engines and operating methods, cooling of the waste gas as needed can be performed only very insufficiently.
It is therefore the object of the present invention to create a method and an internal combustion engine, wherein highly efficient mixing between exhaust gas and fresh air for supply to the internal combustion engine is possible.